Apparatus for sizing photographic paper



Sept. 6, 1938. J. c. TRAHEY 2,129,249

APPARATUS FOR SIZING PHO TOGRAPHIC PAPER Filed March 27, 1937 25 Fig. 2.

John C.Trahe;y

INVENTOR.

Patented Sept. 6, 1938 2,129,219 APPARATUS FOR SIZING PHOTOGRAPHIO PAPER.

John 0. Trahey, Rochester, N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application March 27, 1937, Serial No. 133,423,

7 Claims.

This invention relates to paper making, and particularly to apparatus for sizing photographic paper.

One object of my invention is to provide a paper sizing apparatus through which a sheet of paper may pass continuously at the same rate of speed as it passes through the paper making machine. Another object of my invention is to provide'an apparatus for sizing paper in which the paper is treated with a mixture of gas and air to prepare it for receiving the sizing solution.

Another object of my invention is to provide an apparatus in which steam and hot air may be mixed in various predetermined proportions in order to prepare the paper to receive a predetermined amount of the sizing solution, and other objects will appear from the following specification, the novel features being particularly pointed out in the claims at the end thereof.

In my copending application Serial No. 133,422 filed March 2'7, 1937, for A method of sizing photographic paper, I have described in detail a method for controlling the quantity of size taken up by the paper as it passes through a bath.

Fig. 1 is a front elevation of a pretreatment chamber connectedto the gas mixer constructed so in accordance with and embodying a preferred form of my invention.

Fig.2 is a side elevation of the apparatus shown in Fig. 1, parts being shown in section for the sake of clearness.

40 Fig. 3 is an enlarged fragmentary detail of the gas mixing aspirator used in the mixing chamber shown in the preceding figures, and

. Fig. 4 is a top plan view of the gas chamber showing the connections between the gas mixing 46 chamber and the gas chest in which the paper is treated.

My invention consists broadly in moving a sheet of paper through a gas chest and in mixing a condensible and a non-condensible gas and intro 5o ducing it into the chest to pretreat the paper before it enters the sizing bath. By varying the proportions of the gases, difierent sizing effects can be obtained.

Referring to the drawing, the gas chest is 65 designated broadly as I. I prefer to form this chest in two sections 2, which may be separated upon a line 4 through the center of the chest. The two sections may be separated for threading the paper through the machine, and, if desirable, the sections may be held together in any suitable 5 way, as by set screws 2'. I

I prefer to provide a roller 6 mounted on suitable brackets extending across the top of the chest, and a second roller I mounted on the bottom-of the chest. This roller will normally 10 be immersed in the sizing solution In which is placed in the sizing bath II. The paper 5, as indicated in Fig. 2, passes over theroller 6 down between the lips 8, which extend across the top of the gas chest, through the gas chest and out 15 into. the size l0, passing around the roller I. From this roller the paper may pass through the sizing bath around a roller 30, and then out of the bath between the usual squeeze rolls.

In accordancewith my invention, I desire to pretreat the paper while it passes through the gas chest I, by mixing a condensible gas-steam with a non-condensible gasair--and by varying the proportions. of these two gases, different sizing effects are obtained.

It is possible to treat the paper-web with steam alone and very satisfactory results can be obtained with this method. However, it has the disadvantage of making it necessary to alter the viscosity of the sizing solution, or alter the amount of steam passed into the gas chest, in order to vary widely the amount of size which may be taken up by the paper.

With the apparatus which I have shown in this application, a very wide range of sizing can be obtained. If the paper is treated with steam alone, the maximum amount of size is taken up treat the paper.

It is necessary to thoroughly mix the steam and air before it passes into the gas chest, and it is preferable to heatthe air so that its temperature I will not vary a great deal from the temperature of the steam. To accomplish this, I provide a mixing chamber l8 which, in the present instance, is

aspirator is. This aspirator is fed from a steam pipe 20, so that the nozzle'2l directs a jet of steam through the aspirator IS. The amount of steam admitted to the pipe may be controlled by the valve 25. I have found that entirely successful results can be obtained when the steam is at a pressure of approximately two to four pounds, although, of course, the pressure of the steam can be readily altered within wide limits, providing the other-factors which effect sizing are properly adjusted.

Air is admitted to the aspirator through the pipe 24, which surrounds the steam pipe 29, and which is introduced by means of the pipe 22 in which there is a valve 23. The air may be drawn in through an air intake in the form of a box 26 which is preferably equipped with an air filter, such as a glass filter 21., so that all impurities will be removed from the air.

In order to heat the air, it is passed from the intake up through a tubular air heater which may conveniently be formed of a pipe of sufilcient diameter to encircle a high-pressure steam pipe 29. Thus, as the air moves upwardly through the air heater 28, the steam in the pipe 29 raises the temperature of the air to that, or nearly that of the steam.

The gas mixer I8 is preferably connected to a T-shaped end l1, each end of which is connected by a flexible pipe IE to a header I5. From this header a series of pipes I3 having perforated distributing heads l3 lead into the. gas chest. Each of these leaders is controlled by a valve I, so that, if desired, the amount of gas admitted to one side of the chest may be made smaller or made greater than the amount introduced to the opposite side of the chest, Of course, since it is desirable to have the mixed gases moving at a comparatively high speed, the gases will be mixed pretty thoroughly in the chest, whether or not the headers are separately controlled but, nevertheless, it is desirable to have the valves H for at least an initial adjustment of the apparatus.

In setting this apparatus in operation, the paper 5 is first threaded through the gas chest after being passed around the rollers 6 and 1. It should be noted that the two sections of the gas chest may fit comparatively loosely together because it is desirable to have the gases flow rapidly through the chest. Thus, the lips 8 alone may be spaced apart some distance-such as a quarter of an inch-or the lips, as well as the side edges .4 of the chest may be also spaced apart. It is probable that the fast moving gas drives out all of the air in the interstices of the paper sheet so that the air is replaced by the mixed gases. As soon as this sheet passes into the sizing bath, the mixed gases are replaced by the size. Thus, the gases in the sheet, as it passes into the size bath, control the amount of sizing which the sheet will take up.

As above explained, ii steam alone is used, so

that substantially all of the air is driven out of the interstices of the sheet, a very large amount of sizing is taken up by the sirable for some types of paper, but, of course, it is comparatively expensive. There are certain types of paper in which less sizing can be used to advantage, so that in accordance with the present invention, the amount of sizing can be reduced by mixing air with the gas. As soon as the paper has been threaded and the machine has been started, the valve is open to admit steam and the valve 23 may be partially opened to admit some air. As the first part of the paper web is sized, small sheet. This is very de-' samples can be torn or punched from the paper, and these samples can be tested to determine their moisture content, this indicating the amount of size taken up by the paper. It the amount of size required should be indicated by a 35% moisture content and it is found that the tests indicate the paper only has a 30% moisture content, the amount of air introduced may be decreased by closing the valve 23 slightly more than its setting. This will reduce the amount of air drawn in by the aspirator, and as the amount of steam increases, the paper will take up more of the sizing solution.

With this apparatus it has generally been found possible to control the size within wide limits, by

allowing the valve 25 to always remain in the same position and by adjusting only the valve 23. However, it may sometimes become necessary to adjust both of these valves to get the desired efiect with diirerent grades and types of paper web.

I have also found it possible to keep the viscosity of the sizing solution at substantially the same point for large varieties of sizing eiIects, as, for example to use pounds of size to 100 gallons of water. When the sizing bath is kept uniform and the amount of steam admitted to the gas chest is kept uniform, it is a very simple matter for even an inexperienced operator to control the amount of size to be taken up by the paper.

What I claim as my invention and desire to be secured by Letters Patent of the United States is:

1. An apparatus for sizing paper comprising in combination, a tank adapted to contain sizing solution, a gas chest having a paper inlet above and a paper exit below the surface of the size, a gas inlet to the chest, a source of steam connected to the chest, 8. source of air connected to the chest, means included in the steam and air connections for initially mixing the gases before said gases are passed into the chest.

. 2. An apparatus for sizing paper comprising in combination, a tank adapted to contain sizing solution, a gas chest having a paper inlet above and a paper exit below the surface of the size, a gas inlet to the chest, a source of steam and a source of hot air connected to the gas inlet, a mixing chamber including an aspirator for mixing the two gases, valves for controlling the flow 01' the two gases, said gas inlet being adapted to pass the mixed gases to the chest.

3. An apparatus for sizing paper comprising in combination, a tank adapted to contain sizing solution, a gas chest having a paper inlet above and a paper exit below the surface of the size, a gas inlet to the chest, a source oi. steam and a source of hot air connected to the gas inlet, a mixing chamber including an aspirator for mixing the two gases, valves for controlling the 'flow of the two gases, said gas inlet being adapted to pass the mixed gases to the chest, and a, plurality of distributing heads for the gas inlet to evenly distribute the mixed gases inside of the chest.

. 4. An apparatus for sizing paper comprising in combination, a tank adapted to contain sizing solution, a gas chest having a paper inlet above and a paper exit below the surface of the size, a as inlet to the chest, a source of steam and a source of hot air connected to the gas inlet, a mixing chamberincluding an aspirator for mixing the two gases, valves for controlling theflow of the two gases, said gas inlet being adapted to pass the mixed gases to the chest, and a plurality of distributing heads for the gas inlet to evenly distribute the mixed gases inside of the chest, and a separate valve controlling the mixed gases passing through each distributing head.

5. An apparatus for sizing paper comprising in combination, a tank adapted to contain sizing solution, a gas chest having a paper inlet above and a paper exit below the surface of the sizing solution, a gas inlet to the chest, a gas mixing chamber attached to the inlet, said mixing chamber comprising an aspirator and including a nozzle, a steam supply connected to the nozzle, an air supply connected to the mixing chamber near'the nozzle, a heater for" heating the air, and means for varying the quantity of air supplied to the mixing chamber whereby predetermined mixtures of these gases may be supplied to the gas chamber to treat paper passing therethrough and into the sizing bath.

6. An apparatus for sizing paper comprising in combinatioma tank adapted to contain sizing solution, a gas chest having a paper inlet above and a paper exit below the surface of the sizing solution, a gas inlet to the chest, a gas mixing chamber attached to the inlet, said mixing chamber comprising an aspirator and including a nozzle, a steam supplyconnected to the nozzle, an air supply connected to the mixing chamber near the nozzle, and means for varying the quantity of air supplied to the mixing chamber, a plurality of valve. controlled pipes carried by the inlet to the gas chest whereby the. paper may be treated with the gas mixture before entering the sizing solution.

7. An apparatus for sizing paper comprising in combination, a tank adapted to contain sizing solution, a gas chest having a paper inlet above and a paper exit below the surface of the size, a gas inlet to the chest, means for mixing gases connected to the gas inlet to the chest, a source of non-condensible gas and a source of condensible gas, pipes leading to the sources of the gases and to the means for mixing the gases, and means for varying the proportlonsofthe gases admitted to the means for mixing the gases whereby a, predetermined mixture of the gases may be admitted to the chest for treating paper passing therethrough.

. JOHN C. TRAHEY. 

